Letter Fifty-seven announces Valmont's success in securing Danceny's complete confidence. Now he and the Marquise will have full access to Cécile and the Chevalier's affair. Valmont also suggests that the Marquise should leave her current lover and try him out for a little while.

In the mean time, Valmont has not left off writing to the Présidente (Letter Fifty-eight). He resists her request that he break off their correspondence, claiming that it is his one last pleasure in life. His one wish, he says, is to devote himself to her and her happiness for the rest of time.

The Vicomte continues to entertain himself with Danceny's problems. He writes to Merteuil (Letter Fifty-nine) that the Chevalier has just reported some terrible tragedy in his love affair, but without specifying what this tragedy can be. The letter in which this is reported, Letter Sixty, is enclosed in Letter Fifty- nine. Valmont also announces that he is about to accept an invitation to travel to a friend's estate.

The Chevalier Danceny reports his distress in Letter Sixty and begs to be allowed to see Valmont to seek his advice.

Cécile explains the cause of her Chevalier's distress in Letter Sixty-one to Sophie: her mother has discovered the affair. Who made her mother suspect, Cécile does not know, but one night Madame Volanges barged into her room and demanded to see the contents of Cécile's writing-desk. The first drawer she opened contained all of Danceny's love-letters.

Madame Volanges spares no time in writing to Danceny (Letter Sixty-two) to demand that he cease and desist making love to her daughter. She also commands him to return all of Cécile's letters to her, as she is returning all of his to him.